Performic acid (PFA) is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

CH₂O₃. It is an unstable colorless liquid which can be produced by mixing

formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid. It has the chemical formula HCOOH and structure . This acid is an important intermediate in chemical synthesis and occurs naturally, most notably in some an ...

with

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...

. Owing to its oxidizing and disinfecting action, it is used in the chemical, medical and food industries.

Properties and applications

Performic acid is a colorless liquid soluble in water, alcohols,

ether In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R� ...

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

chloroform Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and po ...

and other organic solvents. Its strong oxidizing properties are used for cleaving

disulfide bond In chemistry, a disulfide (or disulphide in British English) is a compound containing a functional group or the anion. The linkage is also called an SS-bond or sometimes a disulfide bridge and usually derived from two thiol groups. In inor ...

s in protein mapping, as well as for epoxidation, hydroxylation and oxidation reactions in organic synthesis.Pradyot Patnai
A comprehensive guide to the hazardous properties of chemical substances
Wiley-Interscience, 2007, , p. 128 In the medical and food industries, performic acid is commonly used to disinfect equipment. It is effective against viruses, bacterial spores,

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

, microscopic fungi and

mycobacteria ''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis ('' M. tuberculosis'') a ...

, as well as other

microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...

s such as

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

. The popularity of performic acid as a sterilizer originates from the safe nature of its degradation products, mostly

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

, oxygen and water. The disinfecting action of performic acid is also faster than that of the related compounds

peracetic acid Peracetic acid (also known as peroxyacetic acid, or Percidine) is an organic compound with the formula CH3CO3H. This peroxy acid is a colorless liquid with a characteristic acrid odor reminiscent of acetic acid. It can be highly corrosive. Perac ...

and hydrogen peroxide. The major drawbacks of performic acid are handling dangers related to its high reactivity, as well as instability, especially upon heating, which means that the acid must be used within about 12 hours of it being synthesised.

Synthesis

Performic acid is synthesized by the reaction of

and

by the following

equilibrium reaction In a chemical reaction, chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the sy ...

Synthesis of pure performic acid has not been reported, but aqueous solutions up to about 48% can be formed by simply mixing equimolar amounts of concentrated aqueous reactant solutions. Using an excess of either reactant shifts the equilibrium towards the product side. The aqueous product solution can be distilled to increase the concentration of performic acid to about 90%. This reaction is reversible and can be used for large scale industrial production if accelerated with a

catalyst Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

; however, its temperature must be kept below 80–85 °C to avoid an explosion. The catalyst can be nitric, hydrofluoric, phosphoric or

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...

or their salts; it can also be an organic compound containing at least one

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

group, such as

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an Substituent, R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl ...

Matilla, T. and Aksela, R. 2000 Method for the Preparation of Aqueous Solutions Containing Performic Acid as Well as Their Use. , Issue date: April 11, 2000 or peracetic acid.Preuss, A., Fuchs, R., Huss, M. & Schneider, R. 2001 Aqueous Disinfecting Agent Containing Performic Acid and Peracetic Acid Process for Production and Process for Use Thereof , Issue date: April 3, 2001

Safety

Performic acid is non-toxic; it does irritate the skin, but less so than peracetic acid. Concentrated acid (above 50%) is highly reactive; it readily decomposes upon heating, and explodes upon rapid heating to 80–85 °C. It may ignite or explode at room temperature when combined with flammable substances, such as

formaldehyde Formaldehyde ( , ) (systematic name methanal) is an organic compound with the chemical formula and structure , more precisely . The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as ...

benzaldehyde Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is among the simplest aromatic aldehydes and one of the most industrially useful. It is a colorless liquid with a characteristic almond-li ...

, or

aniline Aniline (From , meaning ' indigo shrub', and ''-ine'' indicating a derived substance) is an organic compound with the formula . Consisting of a phenyl group () attached to an amino group (), aniline is the simplest aromatic amine. It is an in ...

, and explodes violently upon addition of metal powders. For this reason, spilled performic acid is diluted with cold water and collected with neutral, non-flammable inorganic absorbents, such as

vermiculite Vermiculite is a hydrous phyllosilicate mineral which undergoes significant expansion when heated. Exfoliation occurs when the mineral is heated sufficiently; commercial furnaces can routinely produce this effect. Vermiculite forms by the weathe ...

References

{{DEFAULTSORT:Performic Acid Organic peroxy acids